The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery

García-Layana, Alfredo; Gianfranco, Ciufo; Toledo, Estefania; Martínez-González, Miguel Ángel, 1957-; Corella, Dolores; Fitó Colomer, Montserrat; Estruch, Ramón; Gómez-Gracia, Enrique; Fiol, Miquel; Lapetra, José; Serra-Majem, Luis; Pinto, Xavier; Portillo, María P.; Sorlí, José Vicente; Bulló, Mònica; Vinyoles, Ernest; Sala Vila, Aleix; Ros, Emilio; Salas-Salvadó, Jordi; Arós, Fernando

doi:http://dx.doi.org/10.3390/nu9050453

The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery

Citation

García-Layana A, Ciufo G, Toledo E, Martínez-González MA, Corella D, Fitó M. et al. The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery. Nutrients. 2017 May 3;9(5): E453. DOI: 10.3390/nu9050453

Abstract

BACKGROUND: Cataract is a leading cause of vision impairment worldwide, and surgery is the only available treatment. The process that initiates lens opacification is dependent on the oxidative stress experienced by the lens components. A healthy overall dietary pattern, with the potential to reduce oxidative stress, has been suggested as a means to decrease the risk of developing cataract. We aimed to investigate the hypothesis that an intervention with a Mediterranean diet (MedDiet) rather than a low-fat diet could decrease the incidence of cataract surgery in elderly subjects. METHODS: We included 5802 men and women (age range: 55-80 years) from the Prevención con Dieta Mediterránea study (multicenter, parallel-group, randomized controlled clinical trial) who had not undergone cataract surgery. They were randomly assigned to one of three intervention groups: (1) a MedDiet enriched with extra-virgin olive oil (EVOO) (n = 1998); (2) a MedDiet enriched with nuts (n = 1914), and a control group recommended to follow a low-fat diet (n = 1890). The incidence of cataract surgery was recorded yearly during follow-up clinical evaluations. Primary analyses were performed on an intention-to-treat basis. Cox regression analyses were used to assess the relationship between the nutritional intervention and the incidence of cataract surgery. RESULTS: During a follow-up period of 7.0 years (mean follow-up period: 5.7 years; median: 5.9 years), 559 subjects underwent cataract surgery. Two hundred and six participants from the MedDiet + EVOO group, 174 from the MedDiet + Nuts group, and 179 from the control group underwent cataract surgery. We did not observe a reduction in the incidence of cataract surgery in the MedDiet groups compared to the control group. The multivariable adjusted hazard ratios were 1.03 (95% confidence interval [CI]: 0.84-1.26, p = 0.79) for the control group versus the MedDiet + EVOO group and 1.06 (95% CI: 0.86-1.31, p = 0.58) for the control group versus the MedDiet + Nuts group. CONCLUSIONS: To our knowledge, this is the first large randomized trial assessing the role of a MedDiet on the incidence of cataract surgery. Our results showed that the incidence of cataract surgery was similar in the MedDiet with EVOO, MedDiet with nuts, and low-fat diet groups. Further studies are necessary to investigate whether a MedDiet could have a preventive role in cataract surgery.